For years, my younger brother, John, and I fought in the kitchen. At its worst, when we both cooked for a living, the only way to avoid all-out warfare at home was to stick to a rule: Either he cooked or I did.

Three years ago, that all changed. I had just moved back to New York after cooking at Berkeley’s Chez Panisse, and he had left Thomas Keller’s Per Se to co-run the kitchen at Franny’s, a wonderful Italian restaurant in Brooklyn. We’ve never known exactly why we made peace then. Our best explanation is that ugly word—at which I still roll my eyes in contempt—maturity.

When we reached our cease-fire and the smoke cleared, we found something miraculous: While working across the country from each other, we had developed cooking styles that matched—unfussy but festive, dependent on making the most of each ingredient, uncompromisingly efficient.

Ever since, cooking together has been easier than cooking alone, and we look for any excuse to do it. All it takes is the arrival of a season, or certain apples at the market, for a phone call or email to arrive: “Adler, Macoun party with bourbon and cider?!” Or: “T, the first chanterelles! Party on my roof?” Soon, we’re feeding a crew of chefs, musicians and artists, toasting nothing but apples, or mushrooms, or a change in the weather.

That’s how we ended up throwing a winter party at fashion designer Lela Rose’s Tribeca apartment, which she designed for her love of entertaining (a table running the length of the space seats 68). I met Lela two summers ago at a fund-raiser for Edible Schoolyard NYC. We quickly discovered we were kindred spirits—she later hosted the release party for my book, An Everlasting Meal. We invited guests like musician Chris Thile, whom I know from one of his concerts (he hugged me when I told him I used to cook at Chez Panisse); composer Gabriel Kahane, with whom I’ve traded cooking and piano lessons; Gramercy Tavern executive chef Michael Anthony, a great mentor of John’s; plus a host of family and friends.

To make feeding a crowd easy, John and I plan our menus with two things in mind. First, we rely on strategies professional kitchens use to cook a lot of food easily. Second, we look to the wisdom of rustic Mediterranean cuisines, which are full of meals that are beautiful, filling and woven into everyday life.

Scanning the stands of produce and meat, I pick up some eggs, nudge John and say, “Bottarga! Toast.” To which he adds, “Chives!” In those half-formed sentences, we agree to scramble the eggs softly with herbs and serve them on toasts with bottarga (dried mullet roe). I love using eggs in unexpected ways in a meal, born of my time working at New York’s Prune, where eggs show up tossed with pasta on the brunch menu, or as a Parmesan omelet at dinner.

John goes on planning: “I’ll make Toscana.” He means anchovy-heavy chicken liver pâté, a favorite since his time at St. John in London, where odd cuts are prized.

We are comfortable serving two appetizers on toasts. We intentionally use the same ingredient in more than one way—a break from the restaurant prohibition of redundant menus. We use parsley in four dishes, lemon juice in five and bread in various permutations (fresh and toasted; stale and ground).

This allows us to prepare dinner efficiently. For the toasts, one of us will slice enough bread for both. We do the same with peeling garlic and washing herbs. I learned how helpful collaborating on big projects is early in my time at Chez Panisse: One day, I was behind and sweating with anxiety when the sous-chef, who was picking parsley for another dish, assured me, “I’m picking your parsley, too.” (I nearly shook with gratitude.) This simple strategy gives me a bird’s-eye view on the meal and helps me keep track of which dishes use each ingredient.

Our greatest requirement, though, is that the food we serve is wonderful when made ahead and in big batches, something common in restaurants and peasant cuisines. Farro, which I serve in a salad with roasted turnips and their greens, can be dressed hours before the party and left to sit—improving as it absorbs olive oil and vinegar, without our doing anything other than drinking cocktails nearby. It’s no harder to make a lot of farro than a little, something that’s equally true of beans, which I cook until velvety and serve in an herby gratin topped with crisp bread crumbs.

We almost always make a slow-cooked meat as the main course. Bollito misto, the Northern Italian dish of slowly simmered meats, is one of our favorites. It’s an example of how tough cuts, cooked at just below a simmer in water and wine, become luxuriously tender and flavorful.

Our repartee in the kitchen is the only holdover from earlier times, the barbs mingling with reassurances: “Adler, taste those beans for salt, then add half as much as you want to.” “Adler, how burnt did you want these toasts?” What’s understood, though, is, “I trust you to make those beans great,” and “Already pulled the toasts from the oven for you.” As we take off our aprons, wipe our hands and greet our guests, there is the exchange that once seemed impossible: “Well done, Adler.” “Well done, Adler.” And cheers.

Brooklyn, New York–based writer Tamar Adler is the author of An Everlasting Meal: Cooking with Economy and Grace.